All of your issues are from a combination of the wrong discs as well as the wrong pads. The pads that were fitted are also too small.

Whoever went ahead with the brake replacement, despite the new stuff looking nothing like the old stuff they were taking out should, frankly, be shot, or as a minimum never let near a spanner again! Grrr

Your 2nd picture really shows the issue. The tangs of the pads should sit firmly onto the carrier (ideally on thin replaceable stainless steel bent metal carriers - available as what's called a 'fitting kit' in addition to the discs and pads).

It's clear from the 2nd picture, that as soon as the outer pad was thin enough, it was free to depart through the gap between caliper carrier and disc, and potentially away through some poor sod's windscreen. Oh dear.

At least you're safe and not too much harm was done (hopefully that is... there's always that flying brake pad!)

J 1992 RR Classic 3.9 efi Vogue
2014 Disco 4 HSE
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

Whilst not the perfect example of replacing rear brakes on an L322 (there's very little cleaning taking place and normal grease on the slide pins is a no-no in my view) + I don't like compressing the piston with pliers - a wind-back tool is much better!

Having said that, check out this quick video to see how the pads should sit into the caliper carrier, making it impossible for them to exit!



J 1992 RR Classic 3.9 efi Vogue
2014 Disco 4 HSE
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

JCW wrote:

Here are the OP’s photos.

I was going to suggest incorrect discs have been fitted, but they’ve obviously been fitted for a good while before this issue has occurred, so perhaps not. The disc not being located centrally between the carrier does look suspicious though.

As others have said, I can’t see how a piston would fall right out even with zero friction material remaining on the pads. Do you mean it pushed beyond the end of the bore or literally fell out?

Thanks JCW,

Original pics were very helpful and you were bang-on with your diagnosis of incorrect discs being fitted!  1992 RR Classic 3.9 efi Vogue
2014 Disco 4 HSE
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

I know this is stating the obvious but have you checked what has been fitted on the front brakes?

Bodsys brake bible is a very useful bit of reading, lots of tips, torque settings etc.

Will

Is Bodsy's brake bible available in the wiki?

[EDIT] Ahh, I see it is on the disco3 website and specifically for the discovery not the L322/L405 but I suppose some bits might be common.

This happened to me too! Pad shot out on a mini roundabout. Non-vented discs had been installed by previous owner.

Looking at it again I can see how once worn down they can push past the tab grooves into the open space where a vented disk would be and fly off! 2012 TDV8 Vogue (L322)

If you haven't yet bought the coolant sensor, check if the float is at the bottom and if it is then a new bottle is required.